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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2014-2015 Pengutronix, Markus Pargmann <mpa@pengutronix.de>
4 */
5
6#include <linux/clk.h>
7#include <linux/interrupt.h>
8#include <linux/irqchip/chained_irq.h>
9#include <linux/irqdesc.h>
10#include <linux/irqdomain.h>
11#include <linux/irq.h>
12#include <linux/mfd/imx25-tsadc.h>
13#include <linux/module.h>
14#include <linux/of.h>
15#include <linux/of_platform.h>
16#include <linux/platform_device.h>
17#include <linux/regmap.h>
18
19static struct regmap_config mx25_tsadc_regmap_config = {
20 .fast_io = true,
21 .max_register = 8,
22 .reg_bits = 32,
23 .val_bits = 32,
24 .reg_stride = 4,
25};
26
27static void mx25_tsadc_irq_handler(struct irq_desc *desc)
28{
29 struct mx25_tsadc *tsadc = irq_desc_get_handler_data(desc);
30 struct irq_chip *chip = irq_desc_get_chip(desc);
31 u32 status;
32
33 chained_irq_enter(chip, desc);
34
35 regmap_read(tsadc->regs, MX25_TSC_TGSR, &status);
36
37 if (status & MX25_TGSR_GCQ_INT)
38 generic_handle_irq(irq_find_mapping(tsadc->domain, 1));
39
40 if (status & MX25_TGSR_TCQ_INT)
41 generic_handle_irq(irq_find_mapping(tsadc->domain, 0));
42
43 chained_irq_exit(chip, desc);
44}
45
46static int mx25_tsadc_domain_map(struct irq_domain *d, unsigned int irq,
47 irq_hw_number_t hwirq)
48{
49 struct mx25_tsadc *tsadc = d->host_data;
50
51 irq_set_chip_data(irq, tsadc);
52 irq_set_chip_and_handler(irq, &dummy_irq_chip,
53 handle_level_irq);
54 irq_modify_status(irq, IRQ_NOREQUEST, IRQ_NOPROBE);
55
56 return 0;
57}
58
59static const struct irq_domain_ops mx25_tsadc_domain_ops = {
60 .map = mx25_tsadc_domain_map,
61 .xlate = irq_domain_xlate_onecell,
62};
63
64static int mx25_tsadc_setup_irq(struct platform_device *pdev,
65 struct mx25_tsadc *tsadc)
66{
67 struct device *dev = &pdev->dev;
68 struct device_node *np = dev->of_node;
69 int irq;
70
71 irq = platform_get_irq(pdev, 0);
72 if (irq <= 0)
73 return irq;
74
75 tsadc->domain = irq_domain_add_simple(np, 2, 0, &mx25_tsadc_domain_ops,
76 tsadc);
77 if (!tsadc->domain) {
78 dev_err(dev, "Failed to add irq domain\n");
79 return -ENOMEM;
80 }
81
82 irq_set_chained_handler_and_data(irq, mx25_tsadc_irq_handler, tsadc);
83
84 return 0;
85}
86
87static void mx25_tsadc_setup_clk(struct platform_device *pdev,
88 struct mx25_tsadc *tsadc)
89{
90 unsigned clk_div;
91
92 /*
93 * According to the datasheet the ADC clock should never
94 * exceed 1,75 MHz. Base clock is the IPG and the ADC unit uses
95 * a funny clock divider. To keep the ADC conversion time constant
96 * adapt the ADC internal clock divider to the IPG clock rate.
97 */
98
99 dev_dbg(&pdev->dev, "Found master clock at %lu Hz\n",
100 clk_get_rate(tsadc->clk));
101
102 clk_div = DIV_ROUND_UP(clk_get_rate(tsadc->clk), 1750000);
103 dev_dbg(&pdev->dev, "Setting up ADC clock divider to %u\n", clk_div);
104
105 /* adc clock = IPG clock / (2 * div + 2) */
106 clk_div -= 2;
107 clk_div /= 2;
108
109 /*
110 * the ADC clock divider changes its behaviour when values below 4
111 * are used: it is fixed to "/ 10" in this case
112 */
113 clk_div = max_t(unsigned, 4, clk_div);
114
115 dev_dbg(&pdev->dev, "Resulting ADC conversion clock at %lu Hz\n",
116 clk_get_rate(tsadc->clk) / (2 * clk_div + 2));
117
118 regmap_update_bits(tsadc->regs, MX25_TSC_TGCR,
119 MX25_TGCR_ADCCLKCFG(0x1f),
120 MX25_TGCR_ADCCLKCFG(clk_div));
121}
122
123static int mx25_tsadc_probe(struct platform_device *pdev)
124{
125 struct device *dev = &pdev->dev;
126 struct mx25_tsadc *tsadc;
127 struct resource *res;
128 int ret;
129 void __iomem *iomem;
130
131 tsadc = devm_kzalloc(dev, sizeof(*tsadc), GFP_KERNEL);
132 if (!tsadc)
133 return -ENOMEM;
134
135 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
136 iomem = devm_ioremap_resource(dev, res);
137 if (IS_ERR(iomem))
138 return PTR_ERR(iomem);
139
140 tsadc->regs = devm_regmap_init_mmio(dev, iomem,
141 &mx25_tsadc_regmap_config);
142 if (IS_ERR(tsadc->regs)) {
143 dev_err(dev, "Failed to initialize regmap\n");
144 return PTR_ERR(tsadc->regs);
145 }
146
147 tsadc->clk = devm_clk_get(dev, "ipg");
148 if (IS_ERR(tsadc->clk)) {
149 dev_err(dev, "Failed to get ipg clock\n");
150 return PTR_ERR(tsadc->clk);
151 }
152
153 /* setup clock according to the datasheet */
154 mx25_tsadc_setup_clk(pdev, tsadc);
155
156 /* Enable clock and reset the component */
157 regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_CLK_EN,
158 MX25_TGCR_CLK_EN);
159 regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_TSC_RST,
160 MX25_TGCR_TSC_RST);
161
162 /* Setup powersaving mode, but enable internal reference voltage */
163 regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_POWERMODE_MASK,
164 MX25_TGCR_POWERMODE_SAVE);
165 regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_INTREFEN,
166 MX25_TGCR_INTREFEN);
167
168 ret = mx25_tsadc_setup_irq(pdev, tsadc);
169 if (ret)
170 return ret;
171
172 platform_set_drvdata(pdev, tsadc);
173
174 return devm_of_platform_populate(dev);
175}
176
177static int mx25_tsadc_remove(struct platform_device *pdev)
178{
179 struct mx25_tsadc *tsadc = platform_get_drvdata(pdev);
180 int irq = platform_get_irq(pdev, 0);
181
182 if (irq) {
183 irq_set_chained_handler_and_data(irq, NULL, NULL);
184 irq_domain_remove(tsadc->domain);
185 }
186
187 return 0;
188}
189
190static const struct of_device_id mx25_tsadc_ids[] = {
191 { .compatible = "fsl,imx25-tsadc" },
192 { /* Sentinel */ }
193};
194MODULE_DEVICE_TABLE(of, mx25_tsadc_ids);
195
196static struct platform_driver mx25_tsadc_driver = {
197 .driver = {
198 .name = "mx25-tsadc",
199 .of_match_table = of_match_ptr(mx25_tsadc_ids),
200 },
201 .probe = mx25_tsadc_probe,
202 .remove = mx25_tsadc_remove,
203};
204module_platform_driver(mx25_tsadc_driver);
205
206MODULE_DESCRIPTION("MFD for ADC/TSC for Freescale mx25");
207MODULE_AUTHOR("Markus Pargmann <mpa@pengutronix.de>");
208MODULE_LICENSE("GPL v2");
209MODULE_ALIAS("platform:mx25-tsadc");
1/*
2 * Copyright (C) 2014-2015 Pengutronix, Markus Pargmann <mpa@pengutronix.de>
3 *
4 * This program is free software; you can redistribute it and/or modify it under
5 * the terms of the GNU General Public License version 2 as published by the
6 * Free Software Foundation.
7 */
8
9#include <linux/clk.h>
10#include <linux/interrupt.h>
11#include <linux/irqchip/chained_irq.h>
12#include <linux/irqdesc.h>
13#include <linux/irqdomain.h>
14#include <linux/irq.h>
15#include <linux/mfd/imx25-tsadc.h>
16#include <linux/module.h>
17#include <linux/of.h>
18#include <linux/of_platform.h>
19#include <linux/platform_device.h>
20#include <linux/regmap.h>
21
22static struct regmap_config mx25_tsadc_regmap_config = {
23 .fast_io = true,
24 .max_register = 8,
25 .reg_bits = 32,
26 .val_bits = 32,
27 .reg_stride = 4,
28};
29
30static void mx25_tsadc_irq_handler(struct irq_desc *desc)
31{
32 struct mx25_tsadc *tsadc = irq_desc_get_handler_data(desc);
33 struct irq_chip *chip = irq_desc_get_chip(desc);
34 u32 status;
35
36 chained_irq_enter(chip, desc);
37
38 regmap_read(tsadc->regs, MX25_TSC_TGSR, &status);
39
40 if (status & MX25_TGSR_GCQ_INT)
41 generic_handle_irq(irq_find_mapping(tsadc->domain, 1));
42
43 if (status & MX25_TGSR_TCQ_INT)
44 generic_handle_irq(irq_find_mapping(tsadc->domain, 0));
45
46 chained_irq_exit(chip, desc);
47}
48
49static int mx25_tsadc_domain_map(struct irq_domain *d, unsigned int irq,
50 irq_hw_number_t hwirq)
51{
52 struct mx25_tsadc *tsadc = d->host_data;
53
54 irq_set_chip_data(irq, tsadc);
55 irq_set_chip_and_handler(irq, &dummy_irq_chip,
56 handle_level_irq);
57 irq_modify_status(irq, IRQ_NOREQUEST, IRQ_NOPROBE);
58
59 return 0;
60}
61
62static struct irq_domain_ops mx25_tsadc_domain_ops = {
63 .map = mx25_tsadc_domain_map,
64 .xlate = irq_domain_xlate_onecell,
65};
66
67static int mx25_tsadc_setup_irq(struct platform_device *pdev,
68 struct mx25_tsadc *tsadc)
69{
70 struct device *dev = &pdev->dev;
71 struct device_node *np = dev->of_node;
72 int irq;
73
74 irq = platform_get_irq(pdev, 0);
75 if (irq <= 0) {
76 dev_err(dev, "Failed to get irq\n");
77 return irq;
78 }
79
80 tsadc->domain = irq_domain_add_simple(np, 2, 0, &mx25_tsadc_domain_ops,
81 tsadc);
82 if (!tsadc->domain) {
83 dev_err(dev, "Failed to add irq domain\n");
84 return -ENOMEM;
85 }
86
87 irq_set_chained_handler(irq, mx25_tsadc_irq_handler);
88 irq_set_handler_data(irq, tsadc);
89
90 return 0;
91}
92
93static void mx25_tsadc_setup_clk(struct platform_device *pdev,
94 struct mx25_tsadc *tsadc)
95{
96 unsigned clk_div;
97
98 /*
99 * According to the datasheet the ADC clock should never
100 * exceed 1,75 MHz. Base clock is the IPG and the ADC unit uses
101 * a funny clock divider. To keep the ADC conversion time constant
102 * adapt the ADC internal clock divider to the IPG clock rate.
103 */
104
105 dev_dbg(&pdev->dev, "Found master clock at %lu Hz\n",
106 clk_get_rate(tsadc->clk));
107
108 clk_div = DIV_ROUND_UP(clk_get_rate(tsadc->clk), 1750000);
109 dev_dbg(&pdev->dev, "Setting up ADC clock divider to %u\n", clk_div);
110
111 /* adc clock = IPG clock / (2 * div + 2) */
112 clk_div -= 2;
113 clk_div /= 2;
114
115 /*
116 * the ADC clock divider changes its behaviour when values below 4
117 * are used: it is fixed to "/ 10" in this case
118 */
119 clk_div = max_t(unsigned, 4, clk_div);
120
121 dev_dbg(&pdev->dev, "Resulting ADC conversion clock at %lu Hz\n",
122 clk_get_rate(tsadc->clk) / (2 * clk_div + 2));
123
124 regmap_update_bits(tsadc->regs, MX25_TSC_TGCR,
125 MX25_TGCR_ADCCLKCFG(0x1f),
126 MX25_TGCR_ADCCLKCFG(clk_div));
127}
128
129static int mx25_tsadc_probe(struct platform_device *pdev)
130{
131 struct device *dev = &pdev->dev;
132 struct device_node *np = dev->of_node;
133 struct mx25_tsadc *tsadc;
134 struct resource *res;
135 int ret;
136 void __iomem *iomem;
137
138 tsadc = devm_kzalloc(dev, sizeof(*tsadc), GFP_KERNEL);
139 if (!tsadc)
140 return -ENOMEM;
141
142 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
143 iomem = devm_ioremap_resource(dev, res);
144 if (IS_ERR(iomem))
145 return PTR_ERR(iomem);
146
147 tsadc->regs = devm_regmap_init_mmio(dev, iomem,
148 &mx25_tsadc_regmap_config);
149 if (IS_ERR(tsadc->regs)) {
150 dev_err(dev, "Failed to initialize regmap\n");
151 return PTR_ERR(tsadc->regs);
152 }
153
154 tsadc->clk = devm_clk_get(dev, "ipg");
155 if (IS_ERR(tsadc->clk)) {
156 dev_err(dev, "Failed to get ipg clock\n");
157 return PTR_ERR(tsadc->clk);
158 }
159
160 /* setup clock according to the datasheet */
161 mx25_tsadc_setup_clk(pdev, tsadc);
162
163 /* Enable clock and reset the component */
164 regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_CLK_EN,
165 MX25_TGCR_CLK_EN);
166 regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_TSC_RST,
167 MX25_TGCR_TSC_RST);
168
169 /* Setup powersaving mode, but enable internal reference voltage */
170 regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_POWERMODE_MASK,
171 MX25_TGCR_POWERMODE_SAVE);
172 regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_INTREFEN,
173 MX25_TGCR_INTREFEN);
174
175 ret = mx25_tsadc_setup_irq(pdev, tsadc);
176 if (ret)
177 return ret;
178
179 platform_set_drvdata(pdev, tsadc);
180
181 of_platform_populate(np, NULL, NULL, dev);
182
183 return 0;
184}
185
186static const struct of_device_id mx25_tsadc_ids[] = {
187 { .compatible = "fsl,imx25-tsadc" },
188 { /* Sentinel */ }
189};
190MODULE_DEVICE_TABLE(of, mx25_tsadc_ids);
191
192static struct platform_driver mx25_tsadc_driver = {
193 .driver = {
194 .name = "mx25-tsadc",
195 .of_match_table = of_match_ptr(mx25_tsadc_ids),
196 },
197 .probe = mx25_tsadc_probe,
198};
199module_platform_driver(mx25_tsadc_driver);
200
201MODULE_DESCRIPTION("MFD for ADC/TSC for Freescale mx25");
202MODULE_AUTHOR("Markus Pargmann <mpa@pengutronix.de>");
203MODULE_LICENSE("GPL v2");
204MODULE_ALIAS("platform:mx25-tsadc");